An SPO2 monitor is required for the regulation of the oxygen saturation in a patient. Physiological closed loop systems must pass over into a fallback mode in care of any error that generates an unacceptable risk. The recognition of incorrect measured SPO2 values may take place by checking the signal in the SPO2 itself. The manufacturer Masimo provides an index of the signal quality of an SPO2 monitor. If the signal quality drops below a threshold value or the time integral of the signal quality drops below a threshold value, the control system recognizes the need for the fall back mode. However, such SPO2 control systems only send a warning or alarm during phases of unacceptable signal quality such that the oxygenation of the patient can be set manually. Such SPO2 control systems do not provide for the oxygenation of the patient to be set automatically.
US 20100139659 A1 relates to a device and a process for controlling a respirator with inclusion of an oxygen saturation value for compensating a device-dependent time response, a physiological time response and a measuring method-dependent time response. The device-dependent time response, the physiological time response and the measuring method-dependent time response are determined in a continuous sequence and a run time of a change in the oxygen concentration from the metering means in the respirator to the patient is determined and taken into account in regulating the oxygen concentration. The device and process would benefit greatly from increased reliability of measured SPO2 values.